how to kill whatever is running on port 3000 code example

Example 1: kill all server 5000 mac

#First run this, to get port information (with the port you want to kill)
sudo lsof -i :3000 

#Then run this, with <PID> replaced by the value in the column returned by previous command.
kill -9 <PID>

Example 2: mac terminal find process by port

sudo lsof -i tcp:3000